Current advances in recovery and biorefinery of fucoxanthin from Phaeodactylum tricornutum

The growing human population has put significant pressure on the market for food sources and nutritional supplements, necessitating careful consideration of high costs, supply, and long-term sustainability. The same is true for the biorefinery of carotenoids where the high extraction costs significantly raise the end-product costs. Many brown seaweeds and unicellular microalgae contain fucoxanthin, an orange-colored pigment found in their chloroplasts. Because of its several medicinal benefits (anti-cancer, anti-diabetic, anti-oxidant, etc), it is an important carotenoid. As a result, a lot of research is being done on fucoxanthin production and extraction from a variety of macroalgal and microalgal sources. When compared to other microalgae, Phaeodactylum tricornutum, a model diatom, is one of the most abundant producers of fucoxanthin. The focus of this paper is on extracting fucoxanthin from Phaeodactylum tricornutum, with Chaetoceros calcitrans and Isochrysis galbana receiving only a passing mention. The cultivation, harvesting, and drying processes of the aforesaid diatoms are briefly discussed in the upstream processing of fucoxanthin. The final section of this paper discusses various traditional (e.g., maceration extraction, Soxhlet extraction, and steam distillation) and new (e.g., Sc-CO₂, ultrasound, microwave, pressured liquid, enzyme, and electric field-based extractions) extraction procedures for fucoxanthin. Finally, the limitations of present extraction strategies are discussed, as well as the potential for cost-effective technologies such as liquid biphasic flotation (LBF) to be used for fucoxanthin recovery.